I find that the best projects start with a purpose, however what most people don't tell you is that the purpose doesn't always have to be prophetic, necessary or groundbreaking. For a lot of people starting a project can be as simple as the intention:
"I want to blink an LED"
When I joined Leeds Hackspace this was the first concept I was introduced to, along with the Arduino platform. This small and, to me, humble beginning has led me down a path which resulted in a change of job, an introduction into an entirely new community and a world of Technological interest and learning that has took me from an interest in computing and network programming to electronics, 3D printing, scanning and more.
My recent project started with a purpose, (if you're squeamish you may want to clench, skip a sentence or look away) when you visit the doctor for a blood test and they struggle to find a vein, usually there's one nurse that can manage it. You don't expect to be told:
"Usually when it's this difficult, we would go in via your neck, but we can't justify it for this test"
To say that's horrifying is an understatement, so the response that came naturally was obvious to me. I must find a solution to this problem. How on earth can I make my veins easier to find so that I can prevent this in future?
Almost coincidentally, in some occurrence reminiscent of the telephone or television being invented at the same time in two sides of the world, I found my solution quickly. After exhausting the thoughts of ultrasound, radiation or other forms of potentially lethal solutions I happened upon an instructables.
3D printing is only as simple and easy as the tool that you're using, and I quickly discovered that the printer at Leeds Hackspace required some tweaking. Those who're familiar with their own built 3D printer will be no stranger to this concept. After a number of nights tinkering with the settings and observing the temperatures, the 'hot end' required cooling and the heat bed required heating. I feel that I've written stranger sentences.
Finally, the basis of the device is completed. However, now I have to populate it with components! Well, a few online searches and ordering later and I would have the crux of the job. LEDs of the correct wavelength to be able to be absorbed by non-oxygenated blood but reflected by the rest of my skin. Soon, I'll be able to see my own veins.
The hardest part, I soon discovered, was that this portable design for a vein finder was not designed with an internal layout in mind. After a few rather hand-warming shorts later I managed to acquire suitable heat-shrink and seal up the device appropriately. Yes, it runs on two double-A batteries at 1.5volts (rechargeables don't quite have the voltage/current for a setup like this, but that could be adjusted).
In the space of, consolidated, a week, I have something to take to the doctors with me the next time I visit. Thanks to the wavelength (628nm) of the red LEDs it's difficult to capture on a digital camera, but hopefully, they won't be going at me via the neck.
Here are some bonus pictures of the finished product in action:
Turns out it's difficult to digitally photograph the near infra-red spectrum.